<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>数据驱动</title>
</head>

<body>
    <div>商品数量 <input id="goodsnum" /></div>
    <div>商品价格 <input id="goodsprice" /></div>
    <div>小计 <span id="total"></span></div>
</body>
<script>
    let goodsnumInput = document.getElementById("goodsnum");
    let goodspriceInput = document.getElementById("goodsprice");
    let  totalSpan = document.getElementById("total");

    let goodsInfo = new Proxy({},{//可以直接监听整个对象
        set(target,attr,value){ //target表示目标对象  attr表示属性  value表示属性值
            target[attr] = value; //goodsInfo.goodsnum =100 ;  target表示 goodsInfos
            //attr表示goodsnum  value表示100
            complier();
        },
        get(target,attr){
            return  target[attr];
        }
    })

    function  complier(){//解析页面
        totalSpan.innerHTML = goodsInfo.goodsnum * goodsInfo.goodsprice;

    }

    goodsnumInput.oninput = function(){//文本框架有内容改变会触发
        goodsInfo.goodsnum =this.value;  //操作的是 数据
   
    }
    goodspriceInput.oninput = function(){//文本框架有内容改变会触发
        goodsInfo.goodsprice = this.value;//操作的是  数据
    }



</script>

</html>